Biodegradation of commercial cypermethrin by microorganisms isolated from agricultural soils exposed to pyrethroid pesticides

The increasing use of pesticides in agricultural systems is a major contributor to water body pollution. Cypermethrin, a highly toxic insecticide for aquatic organisms, is one of the most commonly sprayed pesticides in small agricultural towns in Bolivian valleys. Therefore, eco-friendly strategies are required to degrade this pesticide. Microorganisms capable of degrading cypermethrin could be used for the remediation of soil and water systems. In this work, fungal and bacterial strains from agricultural soils (Tahuapalca, Bolivia) with the ability to grow with cypermethrin as their sole carbon source were isolated. Their ability to degrade pesticides under static and agitated conditions was studied. Three microbial isolates successfully degraded 74.5% of cypermethrin (1.5 g L-1) in 41 days under static conditions. Agitation during incubation significantly enhanced degradation activity by fungal isolates, achieving 95% degradation of cypermethrin within 10 days. The presence of sucrose as an extra carbon source did not improve cypermethrin degradation under agitated conditions.